Burner for pulverized fuel



Jan. 1-9, 1932. H. A. MARSTON BURNER FOR PULVERIZED FUEL 4 Sheets-Sheet 1 Filed June' 27, 1928 Jan. 19, 1932. MARSTQN 1,841,831

BURNER FOR PULVERIZED FUEL Filed June 27, 1928 4 Sheets-Sheet 2 Jan. 19, 1932. H. A. MARSTON BURNER FOR PULVERIZED FUEL FiledJune 27, 19'8 4 Sheets-Sheet haven? Jan. 19, 1932. H. A. MARSTON BURNER FOR PULVERIZED FUEL Filed June 27, 1928 4 Sheets-Sheet 4 pipe A.

Patented Jan. 19, 1932 UNITED STATES HORACE ARTHUR MARSTON, 0F SUTTON; ENGLAND 'IBURNER FOR' PULVERIZED FUEL "hpplicatiomfiled iune'27, 1928," Serial No.'288,690, and'in GreatBritain July 22, 1927.

"This invention relates to burnersfor pulverized fuel andrefers to burners with which streams of air or steam under pressure are employed for breakingup the body ormass of fueland forcing it out, of the burner.

The chief object of the present invention is to improve the oonstructionand increase the efliciency of such burners and to deliver streams of air or steam to the burner in such a manner that less horse power will be required than hitherto for supplying such stream at the necessary pressure or with the requisite velocity. v

According to the present invention the fuel pipe, which is surrounded by an air or steam supply pipe, isfurnished with a convenient number of spirally airanged ribs, vanes or the like all terminating at diiferent points around the pipe and Witha, seriesof steam or air supply ports which may ,be within the ribs, and the surrounding air or steam supply pipe terminates. at the delivery end of the fuel pipe and maybegprovided with an open ring with inwardly-curved walls or it may compriseia series, of delivery ports whichdo not correspond with one-another axially and are preferably furnished with walls of curved formation.

Referring to the accompanying draw- 1ngs:

' Fig; 1 is alongitudinal section of a burner constructed in accordance with or embodying the present invention,

Fig. 2' is a front end view of the same burner,

Fig. 3 is a longitudinal section of a modifled construction of burn-er, F 4 is a front end view of the burner shown in Fig. 3 and. a

-Fig. 5 isza view showing a-development of the ribs illustrated in Fig. 1. --'Referring first of. all to the embodiment of the invention illustrated in Figs.v 1. and2, the delivery pipe A for the pulverized fuel is conne'ctedwith'a supply pipe A and is arranged concentric with an outer; pipe B through which air or steamis supplied and delivered to" the fuel or fuel mixture from the pipe A, beyond the point of discharge from the Within the fuel supply pipe A which may be of constant or varying diametenlis a-series of Webs, fins or ribs A and these areia-rranged spirally around the interior of .the pipe at intervals which may be irregularly spaced, said ribs terminating. at .diiferentdistances from the outlet of the pipe A (see lifigs. 1 and 5).

Opening into the fuel pipe A are air or steam supply ports A and conveniently these portsare formed within the: ribs A? so that they enter the pipe A atldifierent points. At their rear ends these ports communicate with the pipe B and are controlled =by a rotatable valve C. a

The valve C is in the formof a sleeve which is mountedto rotate on the pipe A and withinan internal ring or collar 6 on the pipe B. The valve Gis furnished with ports-which can be brought into register with the inlet ends of the ports :A This valve C-canbe rotated by handles C to regulate the quantity of air or steam delivered to the orts and the valve can beretained in a justedgposition by: a locking screw C I The outer-air orsteam-deliVery-pipe B is conveniently furnished with a locating flange B for the burner. Air or steam is supplied to the pipe 13 from supplypipesB which open into the rear end-of the pipe B. 1 At the forward end of the pipeB, is mounted: a ring or collar 13 in which'are series of; ports 13:, B separated by webs B [lhe-ringB restsupon the forward end of the fuel pipe A and against a sleeve A mounted thereon.

The ports 13 are arranged concentric with the pipe Awhile the ports B are'arranged eccentrically to said pipe, the walls Bof both series of ports being of oppositely-curved for;- mation.

. As the ports 1 1 13 do'not correspond axially, the fuel velocity willbe retarded owing to; the varying influence of the air or steam emerging from the ports B and B tangentially to the fuel stream in the-case of the latter ports.

The pipe B is also furnished with a series of. free. air-inlet ports- B aarranged'at spaced intervals around its circumference zand these ports are conveniently controlled by a rotatable sleeve valve D having a corresponding series of ports D Handles D are provided for rotating this valve to regulate the supply of air to the ports B Mounted in the fuel supply pipe A to discharge into the fuel delivery pipe A is an air or steam supply pipe E which is adjustable longitudinally to regulate or vary the point of discharge relatively to the fuel pipe A and also with respect to the axis so that it may be concentric to or eccentric to the i his pipe E, which may terminate in a hollow truncated cone or may be of fish-tail configuration, ismounted within two eccentric bushes E E which can be rotated separatel or together. The pipe E is free to be slid longitudinally within the inner bush E and is furnished with a stop collar E The bush E can be fixed in adjusted position by a screw E and the bush E by a similar screw E. 7

An indicator E is preferably provided so that the relative position of the bush E to the pipe E can be determined easily, and the periphery of the bush E may be marked so that its position relatively to the bush E may be ascertained.

Pulverized fuel and air or steam under presure are admitted from their respective sources of suppl to the fuel pipe A and the pil'oi'ections or ri s A will tend to deflect the e to different extents from parallelism with the axis of the pipe, resulting in the fuel trying to pass through the pipe A at different velocities due to the irregular arrangement of the ribs, though this will cease rapidly at the ends of said ribs, resulting in a retarding action on the fuel. This fuel velocity will be further reduced by the currents of airor steam under pressure issuing from the orts A and co-acting in imparting a va mg whirling motion to the mixture passing t rough the pipe A. The turbulent state produced in the fuel will be extended by reason of the incoming flow of fuel and air or steam until the mixture is ejected from the A. Further as the ports A are conizrpeda le this turbulent eifect can be regu- The mixture, on emerging from the pipe, A is subjected to a further independent agitation in the combustion chamber by the air or steam emitted under pressure from the ports B, B This air or steam from the rte B, B is in part diverted by the webs and endeavours to conform to the conditions imposed by the curved walls B of the ports B, B so that the turbulence created will be carried forward into the combustion chamber. The elongated outlines of the ports B, B will exert an action on the stream, and part of the stream from the ports B will take a path circumferential to the fuel pipe A and part from the ports B will take a path tangential to the pipe A.

Directional impulse may also be imparted to the fuel stream by an additional supply of air or steam from the pipe E, which, when advanced towards the pipe A, will cause the stream emerging therefrom to exert rectilinear influence on the fuel passing out of the burner and result in the length of the flame being extended into the combustion zone.

Referring now to the modified construction illustrated in Figs. 3 and 4, the steam or air supply pipe terminates in ,an open ring B havingcurved Walls B so that when the fuel mixture issues from the mouth of the pipe A and expands due to the increase in temperature, a converging stream of air or steam from the pipe B will impinge on it and create a turbulent effect which will reduce the velocity thereof.

The air or steam ports in this construction are not extended throughoutthe ribs A but are connected by pipes A with a supply or distributing chamber A to which steam or air is supplied through pipes A from the main supply pipes B and controlled by valves B.

An independent supply of air or steam may be admitted to the distributing chamber A from a supply pipe B controlled by a valve B and branch pipes B which are couple with the pipes A.

When the alternative supply from the pipe B is used alone, the valves B are closed and the valve B" is opened, and when the supply from the pipe B is used in conjunction with a portion of the stream by-passed from the pipes B the valves B are adjusted to the necessary requirements, thus providing a very variable control over the turbulence produced in the fuel stream.

By adjusting the valves B in conjunction with the valve B the intensity of the directional turbulence created in the fuel pipe A can be varied and the direction of the fuel stream may be diverted. As in the first form, the pipe B is furnished with a circumferential series of air-inlet ports B arranged at spaced intervals, said ports being controlled lfiy a rotatable sleeve valve D having ports Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed I declare that what I claim is 1. In a pulverized fuel burner, the combination of a fuel pipe; a fluid pipe extended beyond the fuel pipe at its delivery end and surrounding said fuel pipe; and spaced hollow ribs communicating with the fluid pipe to extend angularly within the fuel pipe with their outer ends opening thereinto in the direction of the delive end; said extended portion of the fluid pipe having eccentric ports converging toward the delivery end of the fuel pipe.

2. In a pulverized fuel burner, the combination of a fuel pipe; a fluid pipe extended beyond the fuel pipe at its delivery end and surrounding said fuel pipe; spaced hollow ribs communicating with the fluid pipe to extend angularly within the fuel pipe with their outer ends opening thereinto in the direction of the delivery end; said extended portion of the fluid pipe having eccentric ports converging toward the delivery end of the fuel pipe; and means for controlling the flow of fluid to the ribs.

3. In a pulverized fuel burner; the combination of a fuel pipe; a fluid pipe extended beyond the fuel pipe at its delivery end and surrounding said fuel pipe; spaced hollow ribs communicating with the fluid pipe to extend angularly within the fuel pipe with their outer ends opening thereinto in the direction of the delivery end; said extended portion of the fluid pipe having eccentric ports directed toward the delivery end of the fuel pipe; means for controlling the flow of fluid to the ribs; and means for regulating the flow of fluid to the eccentric ports.

4. In a pulverized fuel burner; the combination of a fuel pipe; a fluid pipe extended beyond the fuel pipe at its delivery end and surrounding said fuel pipe; spaced hollow ribs communicating with the fluid pipe to extend angularly within the fuel pipe with their outer ends opening thereinto in the direction of the delivery end; said extended portion of the fluid pipe having eccentric ports directed toward'the delivery end of the fuel pipe; means for controlling the flow of fluid to the ribs; means for regulating the flow of fluid to the eccentric ports; and a second fluid supply pipe arranged axially 0f the fuel pipe. 7

5. In a pulverized fuel burner; the combination of a fuel pipe; a fluid pipe extended beyond the fuel pipe at its delivery end and surrounding said fuel pipe; spaced hollow ribs communicating with the fluid pipe to extend angularly with the fuel pipe with their outer ends opening thereinto in the direction of the delivery end; said extended portion of the fluid pipe having eccentric ports directly toward the delivery end of the fuel pipe; means for controlling the flow of fluid to the ribs; means for regulating the flow of fluid to the eccentric ports; a second fluid pipe arranged axially of the fuel pipe; and means permitting adjustment of the sec ond fluid pipe longitudinally of the fuel pipe.

In testimony whereof I aflix my signature.

HORACE ARTHUR MARSTON. 

